Quantitative detection of peroxide formation during oxygen reduction on platinum in alkaline media

Abstract

We quantitatively detected the formation of peroxide during oxygen reduction on oxidized platinum in alkaline media, using the rotating ring-disc electrode rrde technique and the cyclic potential ring measurement (CPRM) method. In the CPRM technique, the ring electrode is continuously cleaned by sweeping it anodically and cathodically to the peroxide detection potential. In this manner, the peroxide intermediate formed during oxygen reduction at the disc electrode is quantitatively detected. Using the CPRM technique we measured ring currents representing larger fractions of peroxide formation at the disc compared to previously reported values using the conventional technique. We measured peroxide yields of 50–60% of the disc current, compared to peroxide yields of ∼ 20–25% using the conventional rrde technique. We conclude that peroxide has a greater role in oxygen reduction on oxidized platinum in alkaline media than previously reported.